Touch sensitive input devices for electronic devices are known generally. U.S. Pat. No. 7,190,350 entitled “Touch Screen with Rotationally Isolated Force Sensor,” for example, discloses a touch screen with one or more sensors that determine the location of touch inputs on the screen. U.S. Pat. No. 7,190,350 also discloses is a pliable material that reduces the effects of distortion on the determination of the touch location.
A challenge with many input devices capable of sensing a force applied normal to a surface of the device is to reduce unnecessary pre-loading of the sensor during assembly. This problem is inherent with sensors that measure force using displacement or strain. Examples of such sensors include force sensitive resistors, strain gauges and capacitive force sensors among others. Also, in some input device applications, it is desirable to sense lateral force or displacement and/or to sense rotation. A joystick is an example of a known input device that may sense these types of inputs. However current joysticks tend to be bulky and are not easily implemented in relatively thin form factors, for example those required in cellular telephones and other thin portable electronic devices. Further, existing input device applications are associated with the significant drawback that the control does not take into consideration the environment or the operating situation in which the device is used or in which identification is performed.
The various aspects, features and advantages of the invention will become more fully apparent to those having ordinary skill in the art upon a careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.